近年來，環保意識抬頭，電動車蓬勃發展，由於汽車上同時存在 12 V 與 48 V 系統，因此本文設計可調節功率的雙向直流/直流轉換 器，主要功能為調度車內 12 V 系統與 48 V 系統間的能量。藉由此轉 換器之設計，電能可以根據負載需要雙向傳輸來滿足車內不同的電壓 系統，並同時有相當高的轉換效率。 本 文 的 硬 體 架 構 主 要 為 交 錯 式 (Interleaved) 同 步 整 流 (Synchronous Rectification)雙向轉換電路，採用 Linear 公司(已於 2016 年被 ADI 併購)所生產之型號 LTC3871 晶片，其擁有電路軟啟動(Soft Start)、電壓電流動態調節、過壓過流保護、熱停機(Thermal Shutdown) 及多相均流機制(Current-Sharing mechanism)等功能。此晶片獨立運作 時最高切換頻率可達 550 kHz，亦能利用其內部之鎖相迴路(Phase Lock Loop)產生最高 460 kHz 的同步訊號執行高達 12 相(6 個 IC，每 個 IC 有 2 相)之連動操作，使其能在高頻下工作減少被動元件的體 積，充分利用車內侷限的空間並同時滿足高功率之需求；此外，也配 合同步整流技術進一步提高轉換效率。;In recent years, the awareness of environmental protection has risen and electric vehicles have flourished. Due to the presence of both 12 V and 48 V systems in automobiles, this paper designs a bidirectional DC/DC converter with adjustable power. The main function is to dispatch the energy flow between 12V and 48V system in the automobile. With the design of this converter, electric energy can be transmitted in both directions according to load requirements to meet different voltage systems in the car, and at the same time, it has a fairly high conversion efficiency. The hardware architecture of this article is mainly an interleaved synchronous rectification (Synchronous Rectification) two-way conversion circuit, using the model LTC3871 chip produced by Linear Corporation (which was acquired by ADI in 2016), which has a soft start circuit (Soft Start) , Voltage and current dynamic adjustment, overvoltage and overcurrent protection, thermal shutdown (Thermal Shutdown) and multi-phase current-sharing mechanism (Current-Sharing mechanism) and other functions. The maximum switching frequency of this chip can be up to 550 kHz when it operates independently, and it can also use its internal Phase Lock Loop to generate a synchronization signal of up to 460 kHz to perform up to 12 phases (6 ICs, each IC has 2 phases) The interlocking operation enables it to work at high frequencies to reduce the volume of passive components, make full use of the limited space in the car and meet the demand for high power at the same time; in addition, it also cooperates with synchronous rectification technology to further improve the conversion efficiency.
